Y-chromosomes and the extent of patrilineal ancestry in Irish surnames
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Ireland has one of the oldest systems of patrilineal hereditary surnames in the world. Using the paternal co-inheritance of Y-chromosome DNA and Irish surnames, we examined the extent to which modern surname groups share a common male-line ancestor and the general applicability of Y-chromosomes in uncovering surname origins and histories. DNA samples were collected from 1,125 men, bearing 43 different surnames, and each was genotyped for 17 Y-chromosome short tandem repeat (STR) loci. A highly significant proportion of the observed Y-chromosome diversity was found between surnames demonstrating their demarcation of real and recent patrilineal kinship. On average, a man has a 30-fold increased chance of sharing a 17 STR Y-chromosome haplotype with another man of the same surname but the extent of congruence between the surname and haplotype varies widely between surnames and we attributed this to differences in the number of early founders. Some surnames such as O’Sullivan and Ryan have a single major ancestor, whereas others like Murphy and Kelly have numerous founders probably explaining their high frequency today. Notwithstanding differences in their early origins, all surnames have been extensively affected by later male introgession. None examined showed more than about half of current bearers still descended from one original founder indicating dynamic and continuously evolving kinship groupings. Precisely because of this otherwise cryptic complexity there is a substantial role for the Y-chromosome and a molecular genealogical approach to complement and expand existing sources.
KeywordsShort Tandem Repeat Short Tandem Repeat Locus Partial Mantel Test Year Before Present Short Tandem Repeat Mutation
We gratefully acknowledge the financial support of Patrick Guinness and Joseph A. Donohoe, through the Trinity Trust, for this research. We thank volunteers for their participation, L.T. Moore for access to pre-published Irish Y-chromosome data as well as K.H. Wolfe, C. Tyler-Smith, M.A. Jobling and T.E. King for helpful discussion.
- Byrne FJ (2001) Irish kings and high-kings. Four Courts Press, DublinGoogle Scholar
- Kim YJ, Paik SG, Ahn GS, Kim W (1999) 49a/TaqI haplotypes according to the surname groups in Korean population. Korean J Genet 21:181–192Google Scholar
- MacLysaght E (1985a) Irish families: their names, arms and origins. Irish Academic Press, DublinGoogle Scholar
- MacLysaght E (1985b) The surnames of Ireland. Irish Academic Press, DublinGoogle Scholar
- Moore LT, McEvoy B, Cape E, Simms K, Bradley DG (2006) A Y-chromosome signature of hegemony in Gaelic Ireland. Am J Hum Genet 78(2): (Epub December 2005)Google Scholar
- Nicholls KW (2003) Gaelic and gaelicized Ireland in the Middle Ages. Lilliput Press, DublinGoogle Scholar
- Rosenberg MS (2001) PASSAGE. Pattern analysis, spatial statistics, and geographic exegesis, version 184.108.40.206. Department of Biology, Arizona State University, ArizonaGoogle Scholar
- Schneider S, Roessli D, Excoffier L (2000) ARLEQUIN version 2.000: software for population genetic analysis. Genetics and Biometric Laboratory, University of Geneva, SwitzerlandGoogle Scholar
- Woulfe P (1923) Sloinnte gaedeal is gall. Gill, DublinGoogle Scholar